2023-07-28 16:21:22 +02:00
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use chainerror::Context as _;
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2018-12-20 10:08:54 +01:00
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use std::error::Error;
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use std::io;
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2020-03-03 14:37:11 +01:00
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fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
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2018-12-20 10:08:54 +01:00
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Err(io::Error::from(io::ErrorKind::NotFound))?;
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Ok(())
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}
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2023-07-28 16:21:22 +02:00
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chainerror::str_context!(Func2Error);
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2018-12-20 10:08:54 +01:00
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2020-03-03 14:37:11 +01:00
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fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
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2018-12-20 10:08:54 +01:00
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let filename = "foo.txt";
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2020-09-01 21:03:01 +02:00
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do_some_io().context(Func2Error(format!("Error reading '{}'", filename)))?;
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2018-12-20 10:08:54 +01:00
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Ok(())
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}
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2018-12-21 13:50:08 +01:00
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enum Func1ErrorKind {
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2018-12-20 10:08:54 +01:00
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Func2,
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IO(String),
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}
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2018-12-21 13:50:08 +01:00
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impl ::std::fmt::Display for Func1ErrorKind {
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2018-12-20 10:08:54 +01:00
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fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
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match self {
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2018-12-21 13:50:08 +01:00
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Func1ErrorKind::Func2 => write!(f, "func1 error calling func2"),
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Func1ErrorKind::IO(filename) => write!(f, "Error reading '{}'", filename),
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2018-12-20 10:08:54 +01:00
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}
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}
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}
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2018-12-21 13:50:08 +01:00
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impl ::std::fmt::Debug for Func1ErrorKind {
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2018-12-20 10:08:54 +01:00
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fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
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write!(f, "{}", self)
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}
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}
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2019-01-08 15:33:12 +01:00
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impl ::std::error::Error for Func1ErrorKind {}
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2023-07-28 16:21:22 +02:00
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fn func1() -> chainerror::Result<(), Func1ErrorKind> {
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2020-09-01 21:03:01 +02:00
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func2().context(Func1ErrorKind::Func2)?;
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2018-12-20 10:08:54 +01:00
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let filename = String::from("bar.txt");
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2020-09-01 21:03:01 +02:00
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do_some_io().context(Func1ErrorKind::IO(filename))?;
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2018-12-20 10:08:54 +01:00
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Ok(())
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}
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2020-03-03 14:37:11 +01:00
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fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
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2018-12-20 10:08:54 +01:00
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if let Err(e) = func1() {
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match e.kind() {
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2018-12-21 13:50:08 +01:00
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Func1ErrorKind::Func2 => eprintln!("Main Error Report: func1 error calling func2"),
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Func1ErrorKind::IO(filename) => {
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2018-12-20 10:08:54 +01:00
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eprintln!("Main Error Report: func1 error reading '{}'", filename)
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}
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}
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if let Some(e) = e.find_chain_cause::<Func2Error>() {
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2018-12-21 13:50:08 +01:00
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eprintln!("\nError reported by Func2Error: {}", e)
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2018-12-20 10:08:54 +01:00
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}
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eprintln!("\nDebug Error:\n{:?}", e);
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2020-09-01 21:03:01 +02:00
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std::process::exit(1);
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2018-12-20 10:08:54 +01:00
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}
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Ok(())
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}
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